1. Field of the Invention
The present invention relates to an endoscope washing and disinfecting apparatus which detects water leak when the apparatus washes and disinfects an endoscope, and to a leak detection method performed by the apparatus.
2. Description of the Related Art
Endoscopes used for the purpose of examining or treating body cavities need to be washed and disinfected after being used. When an endoscope is used, garbage is attached not only to an outer surface of an insertion portion to be inserted into a body cavity, but also to the interiors of individual tubes, such as an air/water supply tube, a suction tube, a forward water supply tube and a treatment tool inserting tube. Therefore, after being used, the interiors of the individual tubes of an endoscope need to be washed and disinfected without fail, in addition to the outer surface of the endoscope.
When washing processes and disinfecting processes for an endoscope are carried out using an endoscope washing and disinfecting apparatus (hereinafter also referred to as a “washing apparatus”), the endoscope that has been used is placed, first, in a washing and disinfecting sink of a washing apparatus (hereinafter also referred to as a “washing sink”). Then, in order to wash and disinfect the interiors of the tubes of the endoscope, a plurality of supply nozzles of the washing apparatus for supplying fluid into the tubes are connected to a plurality of tube bases which are open in the outer surface of the endoscope. Also, an inner space base communicating with an inner space of the endoscope is connected to a leak detection nozzle for supplying gas. The leak detection nozzle is provided at the washing apparatus, in order to check whether or not holes or the like are formed which permit communication between the inner space of the endoscope and the outside, or, in order to perform leak detection for fining leaking points.
After the washing sink is closed with a cover member and processes are started, a predetermined amount of gas is supplied into the inner space of the endoscope through the leak detection nozzle and the inner space base. Then, pressure in the inner space is measured by a sensor, for example, and thereby leak detection is carried out.
If the leak detection results in “No leak occurred”, washing processes are performed, which are followed by disinfecting processes. In the washing processes, washing solution is supplied into the washing sink until the amount of the washing solution reaches a predetermined level. Then, washing is started to wash the outer surface of the endoscope with the circulation of the washing solution. The washing solution in the washing sink, which has been sucked by a circulation pump, is discharged from the supply nozzles for introduction into the tubes through the tube bases and for washing of the interiors of the tubes.
After the washing processes have been completed, the washing solution on the outer surface of the endoscope and in the tubes is washed away with filtered tap water. The procedure then proceeds to the disinfecting processes, in which disinfectant solution that has been adjusted to have a predetermined concentration is supplied to the washing sink. Then, the disinfectant solution in the washing sink, which has been sucked by the circulation pump, is discharged from the supply nozzles for introduction into the tubes through the tube bases.
After the disinfectant solution has been supplied onto the outer surface of the endoscope and into the tubes, the endoscope is immersed in the disinfectant solution to be disinfected for a while. After the disinfecting processes have been completed, the disinfectant solution is washed away with filtered tap water. Then, air or alcohol is supplied onto the outer surface of the endoscope and into the tubes in order to facilitate drying, whereby a series of processes of the washing apparatus is ended.
Japanese Utility Model Registration No. 3109201 discloses a leak detection apparatus for endoscopes, in which an endoscope is immersed in water stored in a washing sink, and air is supplied into an inner space of the endoscope from an air pump to check damages caused on the endoscope. The leak detection apparatus mentioned above has a pressure sensor. The pressure sensor is provided at a discharge-side tube of a regulating valve which is provided at an air supply tube for supplying air. In the apparatus, a circuit is configured in such a way that a control unit, which has been inputted with alarm signals, outputs a stop instructing signal for an air pump and an alarming instructing signal for a buzzer. Thus, in the case where the regulating valve breaks down during leak detection to permit the pressure in an inner space of the endoscope to exceed a specified value, driving of the air pump is stopped to prevent the endoscope from being broken.
Also, Japanese Patent Application Laid-Open Publication No. 5-168592 discloses a washing apparatus having a leak detection function, in which air is supplied into an inner space of an endoscope while pressure variation is measured, so that air leak from the inner space can be detected, for the detection of water leak of the inner space. The apparatus is provided with a pressure-keeping portion which supplies air to the inner space of the endoscope during washing and disinfecting operation to keep the space in the state of being pressurized. Thus, water can be prevented from leaking into the inner space of the endoscope during the washing and disinfecting operation.